Film magazine light trap



Dec 3, 1940- c. M. MlLLl-:R

FILI MAGAZINE LIGHT TRAP Filed May 9, 1938 2 Sheets-Sheet l w xm mM f NWM 4 IM v M Iwf. 4 54 M .1 m

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ATTORNEY.

Dec. 3. 1940 c. M. MILLER FILM MAGAZINE LIGHT TRAP Filed may 9, 1958 2Sheets-Sheet 2 rig. 6.

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f ik N INVENTOR. Charles M- M'Iler -/f-MJ Patented Dec. 3, 1940 UNITEDSTATES PATENT OFFICE :,zzsszs FILM MAGAZINE uGn'r 'raar Application May9, 1938, Serial No. 206,744 1 claims. (CL zas-17) This invention relatesto nlm magazines such as are used on motion picture cameras and dealswith a light trap for automatically opening and closing the nlmapertures in the magazine.

The conventional nlm magazine for motion picture cameras ordinarilycomprises two compartments. One of the compartments, the feedingcompartment, is used for housing a roll of raw nlm stock and the othercompartment, the take-up compartment, is used for housing the nlm alterit has been exposed. The nim runs continuously from one compartment tothe other -and in so doing must pass out of the feeding compartmentthrough an aperture and after forming a loop for threading in the camerapasses back into the take-up compartment through another aperture. Inpractice it is necessary to keep these two apertures closed when themagazine is not on the camera to prevent light leaking into the magazineand fogging the nlm and even when the magazine is mounted on the camerait is necessary to have a means that closes the apertures into the twocompartments when the camera door is open. It is the primary object ofmy invention to provide a light trap in a nlm magazine, comprising vanesor doors. that may be operated to open and close the nlm apertures sothat the nlm nows freely through the apertures and at the same time themagazine may be used with an unobstructed opening into the camera case.To accomplish this, I provide an improved type of vane for pressing thenlm against the wall of the nlm aperture to shut on' all light fromentering the magazine compartments and also provide an improved meansfor withdrawing the vanes when the camera door is closed, said meansbeing so arranged that it operates from one side of the magazine andleaves an unobstructed opening into the camera case for the nlm loop.

Another object of the invention is to provide a light trap for nlmmagazines which is not operated by the closing of the door but isoperated by the means that locks the door in a closed f position. Afurther object of the invention is to provide a means of the characterdescribed that may be installed or incorporated in any type of motionpicture camera, either large or small.

Other objects and advantages, such as the simplicity of construction,the durability and the effectiveness of the device, will become apparentas the description proceeds in conjunction with the drawings, in which:

Figure 1 is a fragmentary view showing a side elevation of a camera witha magazine in place.

4 4 of Figure 3. showing the cam and lever ar- 10 rangement foroperating the light trap.

Figure 5 is an enlarged view showing in detail the means for operatingthe light trap.

Figure 6 is a view, taken on line tof Figure 7, showing the vanes ordoors that close the apertures and the means for moving the vanes; and

Figure '7 is a section through the vanes, taken on line 1--1 of Figure5, showing the manner of installing the same. y

Brieny stated. the invention comprises a pair of vanes adapted to beslid into and out of position over the magazine nlm apertures in such amanner itiat the apertures are entirely closed and the nlm is pressed upagainst one wail of the aperture. The means for doing this comprises arack and pinion arrangement at one side of the magazine, which isadapted to be operated by a lever on the camera case, said lever in turnbeing actuated by the turning of the locking handle on the camera door.As before stated. it is one of the objects of this invention to providea light trap in nlm magazines, wherein the trap may be opened to allowthe nlm to pass freely therethrough, and at the same time anunobstructed opening into the top of the camera case for the nlm loopmay be used.

Referring to the drawings and more specincally to Figure l, it will beseen that I have shown a fragmentary view of a motion picture cameracomprising. generally speaking, a camera case designated A and amagazine generally designated B. 'Ihe magazine B is provided with twocompartments Il and i2, which may be termed the feeding compartment andthe take-up compartment respectively. The nlm F from the feedingcompartment ii passes over a roller I3 and through a nlm aperture i4 andafter forming a loop for threading in the camera passes back into thecompartment I2 through another aperture i5 in the magazine and overanother roller I6, whereupon it is wound upon a spool I1 in the take-upcompartment. Over the apertures Il and i5 I have incorporated myinvention, which will be more fully described hereinafter. The magazineB is arranged to be mounted upon the camera case A in any suitablemanner and in this instance is shown as being mounted on the case on abase corresponding to line B' of Figure 1.

In Figure 2 I have shown a fragmentary view 5 of the camera case withthe magazine removed.

The case is shown with a iiat surface I8 for receiving the magazine baseB', said at surface being provided with an opening I8 which is disposedso as to come directly beneath and extend under the apertures I4 and Ilof the magazine to allow the film loop to fall freely into the cameracase. Means are ordinarily provided for locking the magazine on thecamera case and are shown here as a thumb nut 28.

'I'he means for closing the apertures I4 and I 5 is best illustrated inFigures 5, 6 and 7. Re-. ferring first to Figure 6, it will be observedthat the aperture I4 is adapted to be closed by a vane or door 2| andthe aperture I8 is adapted to be closed by a similar vane or door 22. Itis to be understood that the apertures I4 and I8 are in the nature ofslots of sumcient dimension to freely pass a motion picture film andterminate in a chamber C. The vanes 2| and 22 are mounted in the chamberC adjacent the ends of the apertures I4 and I8 and are arranged to slidein recesses 23 and 24 respectively formed in the--v end walls of thechamber C, the recesses being for the purpose of insuring a light tightseal and forming a guide. The outer ends o! the vanes may be equippedwith suitable pads 25 and 28, such as felt or velvet, for forming alight tight seal when pressed against the film. These pads may be heldinplace by any suitable means, such as bolts 21. The vanes 2| and 22 areadapted to be reciprocated in the recesses 23 and 24 respectively andfor this purpose I provide a roller 28, mounted on a shaft 28, saidshaft in turn being rotatably mounted in the walls of the chamber C asillustrated in Figure 7 and designated 30. The roller 28 carries aplurality of pins 3| which extend through openings 32 in the vanes 2|and 22. The roller 28 rray be cut away longitudinally as shown anddesignated 33 to allow the 45 vanes 2| and 22 full movement for openingand Aclosing the apertures. In order to close the apertures by the vanes2| and 22, the roller 28 is rotated in the direction of the arrow 34 andthe vanes and roller assume the positions shown by 50 dotted lines inFigure 6. In this position it will be observed that the film F ispressed against the walls 35 and 38 of the chamber C, which may becovered with suitable material 35' and 38', such as felt or velvet, andis held against the walls by 55 the pads 28 and 28, thus forming aperfect light seal. The means for rotating the roller 28 cornprises agear 31 mounted upon the shaft 29, said gear in turn being adapted to beengaged by a` rack bar 38 suitably mounted in a plate 39, which e0 inturn is mounted on the side of the magazine at one end of the chamber C.'I'he rack bar 38 is pressed downwardly by a spring 40, which tends tonormally close the apertures I4 and I5 until an upward force is exertedon the rack 65 bar 38.

The means for applying force to, the rack bar 38 will now be'described.As before stated, it ls one of the objects of this invention to open theillm apertures into the magazine compartments 70 only when the cameradoor is closed and the lock is turnedg, Accordingly, the inventionprovides means in the camera case for moving the rack bar 38. 'I'hemeans for this purpose is illustrated in Figures 1 to 4. Y Here it willbe observed that 75 the camera case A is provided with the flat surfaceI8, upon which the magazine B is adapted to be mounted and, aspreviously described, the fiat surface I8 is formed with an unobstructedopening I9, through which the illm loop drops freely into the cameracase. In order to accomplish the object of this invention. it isnecessary to bring the means for opening and closing the aperture doorsto one side of the opening I9. The camera case A will also be seen tohave a door D of the ordinary construction which opens the side of thecamera for threading the film through the intermittent movement. Thedoor is equipped with a locking device generally designated L Thisinvention embodies means for translating movement from the locking meansL to the rack bar 38 to open the light trap in the magazine. In Figure 3I have shown a detail of the parts of the locking device L. In this viewI have shown the device L as comprising a small shaft 42 'rotatablymounted in the upper edge oi' the door D, said shaft having a handle 43on the outer end thereof and a disc 44 on the inner end. 'I'he disc 44serves the double purpose oi locking the door and of opening the lighttraps. As will be seen in Figure 4, the disc 44 has a nat side 45, whichin effect forms a cam. 'I'he purpose of this ilat side is to pass a pin48 mounted in the camera case A so that it may be caught behind the disc44 when the handle 43 is turned. The other purpose of the cam-shapeddisc 44 is to move a lever 41 pivotably mounted on the camera case asshown at 48'. The free end of the lever 41 engages a pin 4l slidablymounted in the camera case. The pin 48 is arranged to come directlybeneath the rack -bar 38 when the magazine is mounted in operativeposition on the camera case. A small pin 43 working in a slot 50 in thearm 41 may be installed on the camera case to'hold the arm 41 fromdropping down when the camera door is opened. The whole assembly formoving the rack bar 38 will be observed to be mounted on the camera caseand to one side of the opening I3 which permits an unobstructed opening.into the case and allows the nlm from the magazine to drop freelythrough the opening for threading the camera.

In operation the magazine is loaded in the usual manner with thecustomary nlm loop extending between the apertures I4 and Il, theapertures I4 and I5 being closed by the doors 2| and 22 which arenormally closed under the influence of the spring 40 acting on the rackbar I8. 'I'he magazine is then mounted upon the camera case A in theusual manner and after threading the film through the film movementmechanism the door D is shut and locked by turning the handle 43 fromthe dotted position to the full line position in Figure, 1. In turningthe handle 43,'the cam-shaped disc 44 locks the door closed against thepin 46 and at the same time raises the lever 41 which pushes the pin 48against the rack bar 38 and withdraws the vanes i 2| and 22, thusallowing the film free passage through the apertures into and out of thecamera. As long as the camera door is closed and locked, the vanes 2|and 22 remain withdrawn, but as soon as the handle 43 is turned to thedotted line position in Figure` 1, for opening the camera door, thevanes 2| and 22 immediately close the apertures I4 and I5 before thecamera door can be opened. The arrangement of the parts provides astructure that is durable and not easily damaged and has a distinctadvantage, in that the apertures are positively closed before the cameradoor can be opened and are not opened until the camera door is fullyclosed. In addition, the mechanism for operating the light trap being toone side oi' the opening into the camera, an unobstructed opening may beused and the mounting of the magazine on the camera becomes acomparatively simple matter, inasmuch the film loop is dropped directlyinto the camera.

I claim:

1. In a motion picture camera having a camera door with a lock thereon,a film magazine having compartments with film apertures into each ofsaid compartments, light proof doors at each of said compartments andmeans for moving said doors to open and close said apertures by theoperation of the lock on said camera door, said last mentioned meansincluding a lever pivotably mounted on the case of said camera, and acam on said lock adapted to swing said lever upon its pivot upon theoperation of the said lock.

2. In a motion picture camera, a camera case having an unobstructedopening therein adapted to freely receive a nlm loop from a magazine, adoor in said case for threading the nlm in said camera, a turnable lockon said door, a pin slidably mounted in said case adjacent an edge ofsaid opening, a lever pivotably mounted at one end thereof on saidcamera case and having the free end engaging said pin, and a cam memberturnable by said lock arranged to engage said lever and swing the sameon its pivot for moving said pin.

3. In a motion picture camera having a camera case and a lm magazineoperatively attached thereto, there being nlm apertures in said magazineand an unobstructed opening in said case adapted to freely pass a ilmloop from said apertures, a magazine light trap comprising: slidingdoors in said magazine arranged to open and close said apertures; arotatable member mounted in said magazine operatively connected to saiddoors for opening and closing the same upon rotation of said member; apinion at one end of said rotatable member; a rack slidably mounted atone side of said magazine adapted to engage said pinion; a pin slidablymounted in said case for moving said rack; a turnable lock for a door insaid case; and means in said case for moving said pin by turning saidlock.

4. In a motion picture camera having a camera case and a tllm magazineoperatively attached thereto, there being illm apertures in saidmagazine and an unobstructed opening in said case adapted to freely passa nlm loop from said apertures, a magazine light trap comprising:sliding doors in said magazine arranged to open and close saidapertures; a rotatable member mounted in said magazine operativelyconnected to said doors for opening and closing the same upon rotationof said member; a pinion at one end of said rotatable member; a rackslidably mounted at one side of said magazine adapted to engage saidpinion; a pin slidably mounted in said case for moving said rack; aturnable lock for a door in said case; a lever pivotably mounted on saidcase at one end thereof and having the free end engaging said pin; and acam on said turnable lock arranged to engage said lever and move thelever and the pin upon turning said lock when the door is closed.

5. In a motion picture camera. a camera case having a door with aturnable lock thereon, a nlm magazine having film apertures thereinadapted w be mounted on said case, a light tight slidable closure memberfor each of said illm apertures, means for sliding said closure membersto open and close said nlm apertures by turning the lock on said door,said means including a rotatable cylindrical member mounted in saidmagazine, means for connecting said closure members to oppositeperipheral sides of said cylindrical member, and means for rotating saidcylindrical member by turning said lock on said door.

6. In a motionv picture camera, a camera case having a door with aturnable lock thereon, a illm magazine having a film feeding apertureand a tllm receiving aperture therein adapted to be mounted on saidcamera case, a light tight reciprocable closure member for eachaperture, a cylindrical member rotatably mounted in said magazinebetween said closure members, means for operatively connecting one endof each of said closure members to opposite sides of said cylindricalmember, and means for rotating said cylindrical member upon turning saidlock in said door.

7. In a motion picture camera having a camera door with a lock thereon,a film magazine having compartments with nlm apertures in each of saidcompartments, iight proof doors over each of said apertures, and meansfor moving said doors to open and close said apertures by the operationof the lock on said camera door, said last mentioned means including arotatable cylindrical member in said magazine operably oonnected tosaiddoors to open and close the same upon rotation of said member, agear at one end of said cylindrical member, a rack arranged to engagesaid gear, a lever pivotally mounted in said camera case, a cam on saidlock adapted to swing said lever upon its pivot point upon the turningof said lock to engage said rack and rotate said cylindrical member.

CHARLES MELVIN MILIER.

